Methods and apparatus for controlling steering nibble in position controlled steering systems

Abstract

Methods and apparatus for controlling steering nibble in position controlled steering systems are described. A controller is to determine actuator angle data based on steering wheel angle data associated with a steering wheel. The controller is also to determine nibble control angle data based on the steering wheel angle data. The controller is also to determine adjusted actuator angle data based on the actuator angle data and the nibble control angle data. The controller is also to generate a control signal based on the adjusted actuator angle data to apply a torque via an actuator of a position controlled steering system.

What is claimed is: 
     
       1. An apparatus comprising:
 a controller to:
 determine actuator angle data based on steering wheel angle data associated with a steering wheel of a position controlled steering system; 
 determine nibble control angle data by implementing a nibble control process, wherein the controller, in connection with the nibble control process, is to:
 determine wheel frequency data based on detected wheel speed data or detected vehicle speed data associated with the position controlled steering system; 
 determine gain data by applying a gain scheduler to the wheel frequency data; and 
 apply the gain data to the steering wheel angle data to produce scaled steering wheel angle data, wherein the nibble control angle data is based on the scaled steering wheel angle data; 
 
 determine adjusted actuator angle data based on the actuator angle data and the nibble control angle data; and 
 generate a control signal based on the adjusted actuator angle data to apply a torque via an actuator of the position controlled steering system. 
 
 
     
     
       2. The apparatus of  claim 1 , wherein the nibble control process is to reduce steering nibble associated with the position controlled steering system. 
     
     
       3. The apparatus of  claim 1 , wherein the controller, in connection with the nibble control process, is to:
 generate a tuned resonator filter based on the wheel frequency data; and 
 apply the tuned resonator filter to the scaled steering wheel angle data to produce raw nibble control angle data. 
 
     
     
       4. The apparatus of  claim 3 , wherein the controller, in connection with the nibble control process, is to:
 apply a phase lift scheduler to the wheel frequency data to determine phase lift data; 
 determine allpass edge frequency data based on the phase lift data and the wheel frequency data; 
 generate a tuned allpass filter based on the allpass edge frequency data; 
 apply the tuned allpass filter to the raw nibble control angle data to produce compensated nibble control angle data; and 
 apply nibble control gain data to the compensated nibble control angle data to produce the nibble control angle data. 
 
     
     
       5. The apparatus of  claim 1 , wherein the actuator angle data is further based on detected wheel speed data or detected vehicle speed data associated with the position controlled steering system. 
     
     
       6. The apparatus of  claim 1 , wherein the control signal is further based on detected actuator angle data associated with the actuator. 
     
     
       7. The apparatus of  claim 1 , wherein the position controlled steering system is an active front steering system. 
     
     
       8. The apparatus of  claim 1 , wherein the position controlled steering system is a steer-by-wire steering system. 
     
     
       9. A method comprising:
 determining, by executing one or more instructions via a controller, actuator angle data based on steering wheel angle data associated with a steering wheel of a position controlled steering system; 
 determining nibble control angle data by executing one or more instructions via the controller in connection with implementing a nibble control process, wherein implementing the nibble control process includes;
 determining wheel frequency data based on detected wheel speed data or detected vehicle speed data associated with the position controlled steering system; 
 determining gain data by applying a gain scheduler to the wheel frequency data; and 
 applying the gain data to the steering wheel angle data to produce scaled steering wheel angle data, wherein the nibble control angle data is based on the scaled steering wheel angle data; 
 
 determining, by executing one or more instructions via the controller, adjusted actuator angle data based on the actuator angle data and the nibble control angle data; and 
 generating, by executing one or more instructions via the controller, a control signal based on the adjusted actuator angle data to apply a torque via an actuator of the position controlled steering system. 
 
     
     
       10. The method of  claim 9 , wherein implementing the nibble control process reduces steering nibble associated with the position controlled steering system. 
     
     
       11. The method of  claim 9 , further comprising, in connection with the nibble control process:
 generating a tuned resonator filter based on the wheel frequency data; and 
 applying the tuned resonator filter to the scaled steering wheel angle data to produce raw nibble control angle data. 
 
     
     
       12. The method of  claim 11 , further comprising, in connection with the nibble control process:
 applying a phase lift scheduler to the wheel frequency data to determine phase lift data; 
 determining allpass edge frequency data based on the phase lift data and the wheel frequency data; 
 generating a tuned allpass filter based on the allpass edge frequency data; 
 applying the tuned allpass filter to the raw nibble control angle data to produce compensated nibble control angle data; and 
 applying nibble control gain data to the compensated nibble control angle data to produce the nibble control angle data. 
 
     
     
       13. The method of  claim 9 , wherein the actuator angle data is further based on detected wheel speed data or detected vehicle speed data associated with the position controlled steering system. 
     
     
       14. The method of  claim 9 , wherein the control signal is further based on detected actuator angle data associated with the actuator. 
     
     
       15. A non-transitory machine-readable storage medium comprising instructions that, when executed, cause a controller to at least:
 determine actuator angle data based on steering wheel angle data associated with a steering wheel of a position controlled steering system; 
 determine nibble control angle data in connection with implementing a nibble control process, wherein the instructions, when executed, cause the controller, in connection with the nibble control process, to:
 determine wheel frequency data based on detected wheel speed data or detected vehicle speed data associated with the position controlled steering system; 
 determine gain data by applying a gain scheduler to the wheel frequency data; and 
 apply the gain data to the steering wheel angle data to produce scaled steering wheel angle data, wherein the nibble control angle data is based on the scaled steering wheel angle data; 
 
 determine adjusted actuator angle data based on the actuator angle data and the nibble control angle data; and 
 generate a control signal based on the adjusted actuator angle data to apply a torque via an actuator of the position controlled steering system. 
 
     
     
       16. The non-transitory machine-readable storage medium of  claim 15 , wherein the instructions, when executed, cause the controller to implement the nibble control process to reduce steering nibble associated with the position controlled steering system. 
     
     
       17. The non-transitory machine-readable storage medium of  claim 15 , wherein the instructions, when executed, cause the controller, in connection with the nibble control process, to:
 generate a tuned resonator filter based on the wheel frequency data; and 
 apply the tuned resonator filter to the scaled steering wheel angle data to produce raw nibble control angle data. 
 
     
     
       18. The non-transitory machine-readable storage medium of  claim 17 , wherein the instructions, when executed, cause the controller, in connection with the nibble control process, to:
 apply a phase lift scheduler to the wheel frequency data to determine phase lift data; 
 determine allpass edge frequency data based on the phase lift data and the wheel frequency data; 
 generate a tuned allpass filter based on the allpass edge frequency data; 
 apply the tuned allpass filter to the raw nibble control angle data to produce compensated nibble control angle data; and 
 apply nibble control gain data to the compensated nibble control angle data to produce the nibble control angle data. 
 
     
     
       19. The non-transitory machine-readable storage medium of  claim 15 , wherein the actuator angle data is further based on detected wheel speed data or detected vehicle speed data associated with the position controlled steering system. 
     
     
       20. The non-transitory machine-readable storage medium of  claim 15 , wherein the control signal is further based on detected actuator angle data associated with the actuator.